Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true and idempotentHint=true, but the description adds meaningful context: it replaces the alarm's existing wallpaper, plays from KLIPY and is never stored by LFG, and returns an error for a non-KLIPY address. That explains the effect of the destructive write and the external dependency better than the annotations alone. Idempotency itself is not discussed, keeping it from a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences, front-loaded with the core action and followed by the KLIPY constraint and the replacement/storage behavior. Minor phrasing repetition around 'KLIPY GIF' adds a little bulk but nothing extraneous.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a destructive, open-world mutation with no output schema, the description covers the key concerns: what gets replaced, that content is streamed rather than stored, and the failure mode for invalid URLs. A note on the success response or the optional query parameter would round it out further.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema already documents all four parameters, including the optional 'query' field the description never mentions. The description ties the operation to a KLIPY GIF's 'address and id' (gif_url and gif_id), adding only light framing beyond the schema. Baseline 3 is appropriate when the schema carries the detail.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description gives a specific verb and resource — making a KLIPY GIF the wallpaper of an existing alarm — and distinguishes that from sibling operations like set_media or add_media_from_url by stating it works from a KLIPY GIF's address and id. An agent can tell exactly what is set and on what object without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly limits scope to KLIPY GIFs and states that a library look or the person's own upload 'goes on by its id', routing the agent elsewhere. It also states the error condition for a non-KLIPY address. It stops short of naming the specific alternative sibling tool, but the when/when-not boundary is clear.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.